1 High-precision ID-TIMS Cassiterite U-Pb systematics using a low-contamination hydrothermal decomposition: implications for LA-ICP-MS and ore deposit geochronology Simon Tapster 1* , Joshua W. G. Bright 1,2 1. Geochronology and Tracers Facility, British Geological Survey, Keyworth, Nottinghamshire, NG12 5 5GG, UK 2. Department of Chemistry, University of Surrey, Guildford, GU2 7XH, UK *Email: simont@bgs.ac.uk https://doi.org/10.5194/gchron-2019-22 Preprint. Discussion started: 16 January 2020 c  Author(s) 2020. CC BY 4.0 License.